Environment and Biodiversity Conservation
Environment and Biodiversity Conservation tests pollution and its control, global change, the levels and value of biodiversity, threats to species, and conservation strategies used in India and internationally.
Pollution and global change
- Air pollutants include SO2 and NOx, which cause acid rain below pH 5.6; CO binds haemoglobin; particulates damage lungs.
- Eutrophication follows nutrient enrichment; high BOD indicates organic pollution because decomposers consume oxygen.
- Persistent pollutants such as DDT biomagnify along food chains.
- Greenhouse gases include CO2, CH4, N2O and CFCs; the ozone layer is depleted by chlorine from CFCs. The Montreal Protocol (1987) phased out ozone-depleting substances.
Biodiversity
- Biodiversity has genetic, species and ecological levels. India is megadiverse; hotspots include the Western Ghats, Himalaya, Indo-Burma and Sundaland.
- Threats include habitat loss, overexploitation, invasive species, pollution and climate change.
- Conservation may be in situ (national parks, sanctuaries, biosphere reserves) or ex situ (zoos, seed banks, botanical gardens).
- Indian measures include the Wildlife Protection Act 1972, Project Tiger 1973 and the Biological Diversity Act 2002; international instruments include CITES and the Ramsar Convention.
Worked example
If DDT is 0.04 ppm in water, 0.5 ppm in plankton, 2 ppm in small fish and 25 ppm in a fish-eating bird, each step shows increase. The bird concentration is about 625 times the water concentration. The reasoning is that DDT is fat-soluble and poorly excreted, so it accumulates at successive trophic levels.
Traps
High BOD means more organic pollution, not cleaner water; the ozone hole is not the greenhouse effect; CFCs are not the main greenhouse gas; a hotspot is defined by endemism and habitat loss, not species count alone; in situ and ex situ conservation are not interchangeable.